Auto-Filter Factor into exposure solver
Mount a filter and the meter compensates for its light loss automatically.
Where to find it
Viewfinder Filter selector (active filter feeds the solver continuously)
Summary
When a CC, B&W contrast, ND, or any other filter is mounted, its filter factor (light loss in stops) rolls into the exposure solver so the metered shutter and aperture pair already accounts for the filter. No manual adjustment needed.
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How it works
What it does
Pick a filter from the filter selector (a yellow contrast filter, a 4-stop ND, an 80A CC) and the meter immediately compensates for the stops that filter eats. The aperture, shutter, and ISO the meter shows you are the values to dial into your camera with the filter on. You don't add or subtract anything yourself.
How it flows through the solver
Every filter has a filter factor measured in stops of light loss. The solver subtracts that loss from the scene EV before it picks the aperture and shutter pair. So a 1-stop yellow filter on a scene that would otherwise meter at 1/250 at f/8 brings the recommendation to 1/125 at f/8 (or 1/250 at f/5.6, depending on which side of the triangle you priorize).
Custom filters
If you've added a custom filter in the filter editor, its EV loss takes priority over the built-in filter when it's the active selection. So a custom 'Lee 81EF + 0.6 ND' entry with a 2.5-stop loss feeds 2.5 stops into the solver, not the 0.67 stops the built-in 81EF would.
Logging
When you capture a frame to the shot log, the active filter's label and EV loss are saved with the shot. So your roll log shows not just 1/250 at f/8 but 'Yellow filter, 1 stop loss, 1/250 at f/8', which makes scanning back through old rolls much more useful.
What you still control
The meter handles the filter math. You still pick the filter, mount it on the lens, and dial the camera to the suggested settings. The Auto-Filter Factor takes the arithmetic out of your hands so you can think about the picture instead of the stops.